Microstructure evolution and kinetics of B-site nanoparticle exsolution from an A-site-deficient perovskite surface: a phase-field modeling and simulation study

Abstract

The entire picture from segregation to exsolution is described, including effects of composition, PO2 and segregation energy.

Nanoparticle Ex-solution for Supported Catalysts: Materials Design, Mechanism and Future Perspectives

“…11,14,47,71,72 They also discovered that an increase in the fraction of M in the B-site can accelerate the kinetics of nucleation and increase the coverage of stable ex-solved particles, the stable surface coverage, and the size and the surface area of the ex-solved particles. 70 The simulation results are also supported with experimental evidence that a higher number of finer Ru nanoparticles could be observed as Ru increased in concentration the (La, Sr)(Cr, Ru)O3−δ perovskite. 73 As concluded by Jiang et al, 70 𝑝 O 2 plays a critical role in influencing the nucleation and growth of nanoparticles in the ex-solution.…”

“…Alternatively, the kinetics and microstructure evolution of the B-site segregation and nucleation in perovskite structure may be well explained under the phase-field framework. Starting from the 'Poisson-Cahn' theory, which has been used to understand the segregation of defects in the surface layer of perovskites, [66][67][68][69] Jiang et al, 70 16)…”

“…Alternatively, the kinetics and microstructure evolution of the B-site segregation and nucleation in perovskite structure may be well-explained under the phase-field framework. Starting from the "Poisson−Cahn" theory, which has been used to understand the segregation of defects in the surface layer of perovskites, 66−69 Jiang et al 70 For the PM phase, the molar fraction of A is near to 1 with x A = (1 − x P )(1 − x) ≈ 1. 70 Upon reduction, the M ex-solves from the PM surface to form the nanoparticles (NPs), which are rich with M with x A = (1…”

“…11,14,47 The second path can be reached by decreasing the standard chemical potential of M in the surface region μ M,surf 0 than that in the bulk μ M,bulk ) to be more negative). 70 On the basis of this model, Jiang et al concluded that the ex-solution of the B-site dopant M results from the spinodal decomposition, as triggered by surface segregation and expansion of the chemical spinodal region. The impact of p O 2 was also investigated using the phase-field model.…”

Tailored Local Bandgap Modulation as a Strategy to Maximize Luminescence Yields in Mixed‐Halide Perovskites

“…Next, we aim to model the formation of the measured disordered energy landscape measured by following a phase‐field approach [ 19–23 ] based on the Langevin equation …”